 (at the DTE)
 (at the DTE)
 (at the DCE)
 (at the DCE)
CORRECT?
25 PIN D-SUB MALE at the DTE (Computer).
25 PIN D-SUB FEMALE at the DCE (Modem).
| Pin | Name | Dir | Description | Circuit | Paired with | 
|---|---|---|---|---|---|
| 1 |  | Shield | 18 | ||
| 2 | TxD |  | Transmitted Data | BA | 14 | 
| 3 | RxD |  | Received Data | BB | 16 | 
| 4 | RTS |  | Request To Send | CA | 19 | 
| 5 | CTS |  | Clear To Send | CB | 13 | 
| 6 | DSR |  | Data Set Ready | CC | 22 | 
| 7 | SGND |  | Signal Ground | Ground | 21 | 
| 8 | DCD |  | Data Carrier Detect | CF | 10 | 
| 9 |  | Rtrn Receive Sig. Elmnt Timing | DD | 17 | |
| 10 |  | Rtrn DCD | CF | 8 | |
| 11 |  | Rtrn Transmit Sig. Elmnt Timing | DA | 24 | |
| 12 |  | Rtrn Transmit Sig. Elmnt Timing | DB | 15 | |
| 13 |  | Rtrn CTS | CB | 5 | |
| 14 |  | Rtrn TxD | BA | 2 | |
| 15 |  | Transmit Signal Element Timing | DB | 12 | |
| 16 |  | Rtrn RxD | BB | 3 | |
| 17 |  | Receive Signal Element Timing | DD | 9 | |
| 18 | LL |  | Local Loopback | LL | 1 | 
| 19 |  | Rtrn RTS | CA | 4 | |
| 20 | DTR |  | Data Terminal Ready | CD | 23 | 
| 21 | RL |  | Remote Loopback | RL | 7 | 
| 22 |  | Rtrn DSR | CC | 6 | |
| 23 |  | Rtrn DTR | CD | 20 | |
| 24 |  | Transmit Signal Element timing | DA | 11 | |
| 25 |  | Test Mode | TM | 
Note: Direction is DTE (Computer) relative DCE (Modem).
| Contributor: | Joakim Ögren, Greg A. Woods | 
| Source: | RS530 Page at Connectivity Knowledge Platform (Made IT) | 
  Copyright © The Hardware Book Team 1996-2004.
  May be copied and redistributed, partially or in whole, as appropriate.
  Document last modified: 2002-01-13